1. Field of the Invention
The present invention relates to a standard zoom lens in which a negative group is provided on the front side, which includes a wide angle and a medium-tele, which is small in size and which has excellent aberrations, and particularly, to a super-compact zoom lens.
2. Description of the Prior Art
A zoom lens including a wide angle and having a zoom ratio of about two is composed of a negative group provided on the front side and a positive group provided at the rear, and a two-group zoom for performing zooming by varying a space between the two groups is well known. This system has a drawback in that the overall length is extended since the construction thereof is based on the retrofocus type. In order to miniaturize the system as described above, one method is to increase the refracting power of the aforesaid front and rear groups.
However, the above-described method has a drawback in that both the front and rear groups are decreased in focal length, and a space between principal points of the front and rear groups is also proportionally small at the local length at which the front and rear groups are made close to each other, as a result of which the front group lens and the rear group lens come into contact, failing to provide for the longest focal length.
For example, Japanese Patent Application Laid-Open No. 111,013/83 discloses means to overcome the above-described problem, in which patent, the refracting power of both the front and rear groups is great, and means for extending the longest focal length comprises an arrangement wherein a fixed negative lens is arranged at the rear (image side) of the rear group.
In such a case, the refracting power of both the front and rear groups becomes great, entailing a difficulty in correction of aberrations.